Multiple electric switch formed from magnetic elements



A. A. SNAPER Dec. 14, 1965 MULTIPLE ELECTRIC SWITCH FORMED FROM MAGNETIC ELEMENTS Filed Feb. 27, 1964 lOb Q @E Y @Wwvw @fm A MAGNEUCJ CHARGE? POWER 5u PpLy Vtial part of its construction and operation.

United States Patent O 3,223,800 MULTIPLE ELECTRIC SWITCH FORMED FROM MAGNETIC ELEMENTS Alvin A. Snaper, Burbank, Calif. (9722 Casaba, Chatsworth, Calif.) Filed Feb. 27, 1964, Ser. No. 347,796 2 Claims. (Cl. 200-87) The present invention relates in general to electrical switches and more particularly relates to a new type of magnetically-operated electrical switch.

The present invention combines the best features of switches found in the prior art while, at the same time, entirely or substantially eliminating many of the shortcomings or disadvantages encountered among them. Accordingly, the present invention is considered a marked step forward in the electrical switch art. More specifically, as is well-known, the vast majority of the switches in the prior art include a mechanical spring member, whether it be a coil spring or a leaf spring, as an essen- However, the use of such a mechanical spring produces a number of undesirable eifects, among which are what are commonly referred to as bounce and hysteresis failure of the spring.

Bounce is basically a damped oscillation of the spring and is produced when the spring is put into motion at the time one set of contacts is opened and another set closed. Bounce is undesirablebecause it also appears at the newly closed contacts which, in turn, results in transient effects in the electrical output. As to the matter of hysteresis failures, the continued use of a spring over a long period of time ultimately results in la change in the spring tension, thereby reducing the contact pressure and, therefore, the electrical contact between the interconnected elements. Stated ditferently, hysteresis failures result in poor electrical coupling, a condition that is to be avoided if at all possible.

A further problem leading to the early failure of prior art switches is that of Wipage, by which is meant one contact moves across or wipes the surface of another contact when the connection between them is broken or made. While some degree of wipage is desirable because it insures a good electrical contact between the contact surfaces, it is undesirable to the extent that it exists today because it causes Wear and tear and, in a relatively short time, the parts are worn to the point that poor electrical contact between them ultimately results. Finally, notwithstanding the fact that strides have been made in recent years to improve these switch devices, they still usually include, relatively speaking, a sizable number of parts, such as a spring, a mechanism for locking the switch in each of its positions, and the like. This not only increases the cost of such items, but also adversely affects their reliability. Accordingly, there still remains a need to provide a switch whose construction is the quintessence of simplicity.

It is, therefore, an object of the present invention to provide an electrical switch that does not include a mechanical spring as a part of its construction.

It is another object of the present invention to provide an electrical switch in which the problem of bounce is eliminated.

It is a further object of the present invention to provide an electrical switch which is the ultimate in mechanical simplicity.

It is an additional object of the present invention to provide an electrical switch which, because of its mode of operation, permits an extremely large variety of switching arrangements or combinations.

In accordance with the basic concept of the present invention, the abovesaid objectives are achieved by using mangetic forces to provide the needed spring action and also to lock the switch in its different switch positions. Thus, a Ifeature of the present invention is that magnetic forces are substituted for the usual mechanical elements or devices found in electrical switches and the point of novelty in the invention resides in the way this is accomplished. More particularly, lin implementing the invention, a pair of dielectric members are employed that contain particles capable of being permanently magnetized as an inherent part of its composition. By means of magnetic charging apparatus, each of these members are magnetically polarized at a number of different points and by so doing, it can be said for purposes of explanation, each member is thereby provided with the equivalent of bar magnets. Consequently, when these members are placed in face-to-face relationship and one member is moved relative to the other, theyreact to the diiferent magnetic forces involved by being forced apart in some positions and forced together in still other positions. By mounting in one way or another a programmed arrangement of metal strips on the face-to-face surface of each of the members, different switching cornbinations can be obtained that respectively correspond to the different positions of the members when they are in firm contact with each other. I

More specifically, assuming that the switch members are together in one position, then a slight movement of one of the members relative to the other will result in repelling magnetic forces that quickly separate the members and, therefore, the contacting metal strips. A slight further displacement of the moving member will, however, result in strongly attractive magnetic forces being generated that causes the members to snap together in a new position, thereby producing a new combination of contacting metal strips. The members are held firmly inthis position until one is again displaced relative to the other as above-described, and this can be done manually or by some electro-mechanical means, such as solenoid.

A switch constructed in accordance with the principles of the present invention is a very simply constructed switch and, therefore, can be manufactured at reduced cost as compared to other switches of this kind. However, aside from cost, it provides other advantages as previously mentioned. Thus, the elimination of a mechanical spring also eliminates the problem of bounce. In this respect, the forces driving the two members together are strongest when they are together and, therefore, they are held so firmly that there is just no opportunity to bounce. Secondly, while some wipage does occur between opposing metal strips which, as was previously stated, is desirable in order to bring about good electrical contact, wear and tear is reduced to a minimum because only a slight movement or displacement of one member is required in order to quickly separate it from the other member. Furthermore, the effects of wipage are still further reduced here because all the metal strips are worn down over a period of time by substantially equal amounts and, therefore, they still make excellent contact when the two members are pressed together. Again, the magnetic lpolarizations remain undiminished in intensity no matter how long these switches are used, with the result that the present invention also avoids the problem of hysteresis failures normally encountered among earlier type switches.

The novel features which are believed to be characteristic of the invention, both to its organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawing in which a couple of embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawing is for the purpose of illustration and description only and is not intended as a definition of the limits of the invenpresent invention;

FIGURE 5 is a cross-sectional view that illustrates a practical construction for a rotary switch using the FIG. 4 members; and

FIGURE 6 illustrates apparatus and the technique for magnetically polarizing the rotary switch elements of FIG. 4.

For a consideration of the invention in detail, reference is now made to the drawing wherein like or similar parts or elements are given like or similar designations throughout the several figures therein. Referring to the first switch embodiment shown in FIGS. 1 and 2, reference is first made to FIG. 1(a) wherein are shown a pair of at rectangular-shaped members 10 and 11 that is made of a dielectric material containing particles that are capable of being permanently magnetized. By way of example, these particles may be carbonyl iron powders or ferrite powders which are compounded or incorporated into the dielectric base material at the time of its manufacture in order to provide the desired homogeneous distribution. Some manufacturers of this material are the General Tire and Rubber Company of Wabash, Indiana and the B. F. Goodrich Company, Plastics Division, of Marietta, Ohio. Members 10 and 11, as shown, have already been magnetically polarized at different points along their respective lengths in accordance with a predetermined pattern and, in order to facilitate an explanation of the various polarizations and the significance thereof, the members have been swung open to form an open angle although they would normally be in a faceto-face or sandwich arrangement with each other. As presented, the polarized areas on members 10 and 11, such as polarized areas 10a, 10b, 10c, etc., on member 10 and polarized areas 11a, 11b, 11C, etc., on member 11, resemble bar magnets but it must be emphazised that, in fact, they are not separately mounted bar magnets but only narrow strips or areas of the base material that have been magnetically polarized so that they exhibit the magnetic properties of bar magnets with a north pole at one end of a polarized strip and a south end at the other end. As shown in the figure, the polarization on each member is alternating in its pattern, that is to say, the north and south poles alternate in succession along the length of each member. Now, if members 10 and 11 are placed together, one upon the other, like a sandwich, polarized strips 10a, 19b, etc. on member 10 would initially be in registration with polarized areas 11a, 11b, etc. on member 11. Accordingly, in this initial position, the magnetic poles on one member would attract the magnetic poles on the other member which, in turn, would result in the two members being firmly pressed together.

At this stage, however, if either member 10 or 11 were to be moved or displaced length-wise relative to the other, then the polarized areas of the two members would likewise be shifted relative to each other so that the magnetic poles, instead of attracting each other as before, would now oppose or repel each other to thereby forcefully thrust or push the members apart. If the moving l their inside surfaces.

member is now moved still further, magnetic forces of attraction again come into play and, because of it, the members are forced together again in a rm press. By way of specific example, forces of attraction are exerted upon members 10 and 11 when polarized areas 10a and 11a are in registration, forces of repulsion are exerted upon them when polarized area 10b is in registration with polarized area 11a and, finally, forces of attraction are again exerted when polarized area 10c is in registration with polarized area 11a. In connection with these polarized areas, it should be mentioned at this point that the spacings between these areas and the pattern shown are illustrative only and, therefore, that the spacings between them and the order or pattern in which they are arranged may be varied according to need.

Referring now to FIG. 1(b), base members 10 and 11 are shown once again but this time with electrically conductive strips or areas suitably deposited or mounted on Assuming that these conductive strips are made of metal, the strips on one member may vary Widely from the strips on the other member as to number, width, the patterns in which they are arranged, and the like. It is thus seen that metal strips 12a, 12b, 12e nd 12d on member 10 are different in a number of respects, from strips 13a, 13b, 13e and 13d on member 11. In short, the mounting of strips 12 and 13 are programmed in such a manner so as to provide different switching combinations or arrangements as desired. Thus, if members 10 and 11 in FIG. 1(1)) are placed face-toface so that strips 12 and 13 are in contactwith each other and if one of these two members,'preferably member 11, is held stationary while the other member is moved relative to it, then, for the reasons previously explained in connection with FIG. 1(11), the members are forced apart and brought together again in positions that produce the desired switching as progammed. Hence, with the aid of metal strips 12 and 13 and also with the aid of leads or probes 14 connected to strips 13, different circuits may be connected into or disconnected from a system, different voltages may be switched in or out of a circuit or system, or, if desired, some sort of repetitive electrical output may be obtained by periodically repeating the switching cycle, the drive being provided by a solenoid or other suitable drive mechanism.

A practical arrangement for housing the FIG. 1(b) switch is shown in cross-section in FIG. 2 wherein the housing structure is shown to be made up of two parts, namely, a base member 15a on top of which is mounted a cover member 15b. Switch member 11 is xedly mounted in a recess 15a` provided in base member 15a, the depth of the recess being such that the surface of metal strips 13 are at least flush with the inside surface of this base member if not raised very slightly above it. As for member 10, it slidably rests on member 11 and the roof of housing member 15b is raised a little to provide a space 15d into which member 10 can move when it is forced away from member 11. T o provide an opportunity for switch member 10 to be freely moved in a length-wise direction, one end of housing structure 15 remains open and this opening is designated 15e in 4the figure. It should also be mentioned that one side of housing member 15a has openings through it through which leads 14 may extend for external connection. The aforesaid openings are not shown in FIG. 2 because the view therein is in cross-section, but these openings are discernible in FIG. 3 to which reference is now made.

A more extensive switch may be provided by employing two pairs of switch members of the kind shown in FIGS. 1 and 2 and by putting both pairs together, that is to say, by forming a sandwich arrangement of all four members. By so doing and by modifying the FIG. 2 housing slightly to accommodate the increased number of switch members, the larger switch structure shown in FIG. 3 is thereby obtained. Of the four switch members, the two center members, designated 11 and 11,

are fixed in position `while the two outer members, designated and 10, are slidable with respect to them as indicated by the arrows. The housing structure for the FIG. 3 switch is basically two housing structures 15 of the kind shown in FIG. 2 placed back-to-back. Accordingly, to avoid being redundant, no further description of this housing` structure is provided. Suffice it to say, therefore, that two sets of leads 14 and 14'l emerge from the sides of this. larger switch, leads 14 connecting to switch member 11 and leads 14 connecting to switch member 11".

The two basic elements in a second switch embodiment, namely, a rotary switch, are illustrated in FIG. 4 and are designated 16 and 17, member 16 being the rotor and member 17 being the stator. As shown in the figure, members 16 and 17 are both shaped like truncated cones with member 16 being hollow and open at the bottom so that member 17 can be positioned wtihin it. Members 16 and 17 correspond to members 10 and 11 in FIG. 1( b) and except for the fact that members 16 and 17 are designed to allow rotary motion between them, and therefore, to provide a rotary switch, they are basically the same as those in FIG. 1(b). Accordingly, sufiice it to say that the inside surface of rotor 16 and the outside surface of stator 17 are magnetically polarized at different points along their periphery as before and also as before these surfaces have mounted on them metal strips 12 and 13 which engage or disengage each other as the switch is turned to different positions. Leads or terminals 14 by means of which external connections can be made to the switch are likewise connected to strips 13. For reasons that will shortly be made clear, member 17 also includes a cylindrical opening 18 that extends vertically through it at its center.

A practical arrangement of a rotary switch using members 16 and 17 is shown in FIG. 5 wherein member 16 is mounted over member 17 so that the surfaces of these members that are magnetically polarized and on which the electrically conductive strips are mounted are in faceto-face relationship. Extending through opening 18 is a metal shaft 20 whose .head or cap 20a is embedded in the roof of member 16. Shaft 20 fits loosely in opening 18 and, therefore, it moves freely with member 16 as the latter moves up and down, that is to say, toward and away from member 17. Although not absolutely essential, it is nevertheless desirable to limit or restrict the separation between members 16 and 17 and toward this end an element 20h may be mounted or otherwise afiixed to the bottom of shaft 20 for providing a shoulder that will abut against the bottom side of member 17, thereby preventing any further upward displacement of the shaft and member 16.

The operation of the FIG. 5 switch is the same as that for the switch shown in FIG. 2. Thus, by turning member 16, the magnetic forces produced as a result of the polarizations formed on the face-to-face surfaces of the two switch members first forces the two members apart, thereby disengaging their metal strips from one another, and later forces them together, thereby mating a new combination of these metal strips. It will be recognized that the output at any of the leads 14 depends upon which of metal strips 12 are in registration with metal strips 13 and in this regard it will also be recognized that leads 14 may be used both for input and output purposes or else solely as an output in which case metal shaft 20, with its head 20a connected to all strips 12, would be used as the input.

Switch members 16 and 17 may be magnetically polarized in the patterns desired by means of the magnetic charging apparatus of FIG. 6. This apparatus includes a magnet charger 21 and a series of coils 22a, 22b, 22e, etc., wound on a hollow permeable core 23 whose shape is that of a truncated-cone. Coils 22 are electrically connected to magnet charger 21 which sends current of proper magnitude andv polarity through these coilsat selected times. Member 16 fits over core 23 while member 17 fits inside it. Consequently, both members may be subjected to the process of being magnetically polarized at the same time. Equipment for magnetically polarizing members 16 and 17 or for magnetically polarizing members 10 and 11 are commercially available or can readily be adapted from commercially available equipment. For example, the principles Iof operation and construction of magnetic charging equipment are set forth in an article in volume VII, No. l of a technical periodical entitled, Technician, published by Radio Frequency Laboratories, Inc., Boonton, New Jersey, the article being entitled, .The Selection and Use of Magnet Charging and Treating Equipment, by lack M. Janicke. The same company manufactures and sells charging equipment of the kind involved herein and, therefore, has also published technical information and application -data concerning its equipment as, for example, its publication entitled Model 2470 Magnet Charger.

Although a number of particular arrangements of the invention have been illustrated above by way of example, it is not intended that the invention be limited thereto. Rather, the invention should be considered to include all modifications, alterations, variations or equivalent arrangements of an electrical switch 4operated and controlled by means of magnetically polarized areas as herein described and falling within the scope of the annexed claims.

Having thus described the invention, what is claimed is:

1. An electrical switch in which magnetic forces are used to make and break different switch connections, said switch comprising: a first member made of a dielectric material that contains particles homogeneously distributed throughout it that can be permanently magnetized, said first member being mounted in a fixed position and magnetically polarized along a number of areas that extend thereacross with the poles of said polarized areas alternating in a predetermined pattern, said first member including a number of separate and distinct electrically conductive strips mounted in a first pattern on a surface thereof; and a second member made of a dielectric material that contains particles homogeneously distributed throughout it that can be permanently magnetized; said second member being mounted in face-to-face relationship with said first member and movable relative thereto in a direction that is transverse to the direction in which the polarized areas extend on said first member, said second member also being magnetically polarized along a number of areas that extend thereacross with the poles thereof arranged in the same pattern as on said first member, said second mmeber including a plurality of groups of electrically conductive strips that are interlaced with one another mounted Ion a surface thereon, the surfaces of said first and second members on which said strips are mounted being face-to-face with each other, said plurality of groups of electrically conductive strips on said second member being arranged so that they are contacted in succession by the electrically conductive strips on said first member in response to successive displacements in the same direction of said first member relative to said second member.

2. An electrical switch comprising: a housing structure including a base member having a recessed area therein and a cover member having a raised roof and an opening at its front end; a first switch member, having a pattern of magnetically polarized areas thereon, mounted in said recess, said first member including a plurality of separate and distinct electrically conductive strips mounted in a predetermined pattern on its surface; a plurality of electrical leads respectively connected to said plurality of strips on said first member; and a second switch member, having another pattern of magnetically polarized areas thereon, slidably mounted over said first member and extending through the opening at the front end of 8 References Cited by the Examiner UNITED STATES PATENTS 2,896,043 7/ 1959 Andrews 200-67 X 5 BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Acting Examiner. ROY N. ENVALL, JR., Assistant Examiner. 

1. AN ELECTRICAL SWITCH IN WHICH MAGNETIC FORCES ARE USED TO MAKE AND BREAK DIFFERENT SWICH CONNECTIONS, SAID SWITCH COMPRISING: A FIRST MEMBER MADE OF A DIELECTRIC MATERIAL THAT CONTAINS PARTICLES HOMOGENEOUSLY DISTRIBUTED THROUGHOUT IT THAT CAN BE PREMANENTLY MAGNETIZED, SAID FIRST MEMBER BEING MOUNTED IN A FIXED POSITION AND MAGNETICALLY POLARIZED ALONG A NUMBER OF AREAS THAT EXTEND THEREACROSS WITH THE POLES OF SAID POLARIZED AREAS ALTERNATING IN A PREDETERMINED PATTERN, SAID FIRST MEMBER INCLUDING A NUMBER OF SEPARATE AND DISTINCT ELECTRICALLY CONDUCTIVE STRIPS MOUNTED IN A FIRST PATTERN ON A SURFACE THEREOF; AND A SECOND MEMBER MADE OF A DIELECTRIC MATERIAL THAT CONTAINS PARTICLES HOMOGENEOUSLY DISTRIBUTED THROUGHOUT IT THAT CAN BE PERMANENTLY MAGNETIZED; SAID SECOND MEMBER BEING MOUNTED IN FACE-TO-FACE RELATIONSHIP WITH SAID FIRST MEMBER AND MOVABLE RELATIVE THERETO IN A DIRECTION THAT IS TRANSVERSE TO THE DIRECTION WHICH THE POLARIZED AREAS EXTEND ON SAID FIRST MEMBER, SAID SECOND MEMBER ALSO BEING MAGNETICALLY POLARIZED ALONG A NUMBER OF AREAS THAT EXTEND THEREACROSS WITH THE POLES THEROF ARRANGED IN THE SAME PATTERN AS ON SAID FIRST MEMBER, SAID SECOND MEMBER INCLUDING A PLURALITY OF GROUPS OF ELECTRICALLY CONDUCTIVE STRIPS THAT ARE INTERLACED WITH ONE ANOTHER MOUNTED ON A SURFACE THEREON, THE SURFACES OF SAID FIRST AND SECOND MEMBERS ON WHICH SAID STRIPS ARE MOUNTED BEING FACE-TO-FACE WITH EACH OTHER, SAID PLURALITY OF GROUPS OF ELECTRICALLY CONDUCTIVE STRIPS ON SAID SECOND MEMBER BEING ARRANGED SO THAT THEY ARE CONTACTED IN SUCCESSION BY THE ELECTRICALLY CONDUCTIVE STRIPS ON SAID FIRST MEMBER IN RESPONSE TO SUCCESSIVE DISPLACEMENTS IN THE SAME DIRECTION OF SAID FIRST MEMBER RELATIVE TO SAID SECOND MEMBER. 